Process of producing amino-anthraquinones.



- 1 UNITED STATES PATENT OFFICE.

RUnoLF UI-IL E NHLiTH, OF HOCHST-ON-THE-MIET: GERMANY, 'ASSIGNOR. 'ro FARB- vWERKE VORM.-MEISTER LUCIUS & BBTLTNING, or HooHsr-oN-a'nu-MATN. GERr MANY, A CORPORATION OF GERMANY.

PROCESS OF PRODUCING AMINO-ANTHRA QUINONES. i

No Drawing.

Patented J uly28, 1914.

To all whom it may concern Be t known that I, RnnoLr UHLENHUTH,

.Ph. 1)., chemist, a citizen of the Empire of Germany, residing at Hiichst-on-the-lllain, Germany, have mvented certain new and useful Improvements in the Process of Producing Amino-Antilraquinones, of which the place accordingto the equation:

wherein R means an alkali, metal, like potassium, or sodium, or the ammon1umgroup;.

produced by the above-mentioned ,1;.pr0c ess can betransformed during? the operation into a s'alt'which is so little soluble that it no longer impedes the further reaction. In

this way excellent results are obtained, particularly by employing the barium salts of the anthraquinonesulfonic acids in question, or by causing the formation of said salts during the reaction by. the use of alkaline salts of said anthraquinonesulfonic acids "and of soluble barium salts of suitable acids,

zsuch, for instance, as barium ohlorid.

The following examplcsillustrate my invention: I Example I: 4.12 parts of finely powdered sodium anthraquinone-2-sulfonate are introduced into a solution of 2.36 parts of crystallized barium chlorid in 3.1 times as much water, and after having added 20.5 liters of aqueousammonia of 25 per cent. strength this mixture is heated for 48 hours under pressure to 170177 C. The resulting mass, after havingbeen cooled, is filtered (5a and extracted by consecutively boiling with water, diluted hydrochloric acid and a diluted solution of sodium carbonate. Thus there are obtained 2.19 parts of pure crystallized 2-aminoanthraquinone:53.1% of the sodium salt used, or 73.7% of the theoretical quantity. When working under the foregoing conditions but without adding barium chlorid, the yield in Q-aminoanthraquinone does not exceed 50 per cent. of the theoretical quantity. f

Example II 3 parts of potassium anthraquinone l-sulfonatc arc stirred into a solution of 2.25 parts of crystallized barium chlorid in 27 parts of aqueous ammonia of 25 per cent. strength and 3 parts of water, whereupon the mixture is heated for 12 hours to 180-186 C. at a pressure of about '40 atmospheres. The further operation is conducted in the nannerindicatcd in Example I. The yield in pure crystallized 1- aminoanthraquinone amounts to 89% of the theoretical quantity. If 'the operation is conducted. under the above indicated" condi- .;,tions but without adding barium chlorid, the yield in. l-aminoanthraquinone amounts only to When usinganother acid, for instance the 1.5- or 1.8- anthraquinonedisulfonic acid, the procedure is the same as thatjndicated in the foregoing examples.

Having now described my invention'what I claim is:

1. The process for producing aminoanthraquinones, which consists in heating an anthraquinonesulfonic acid with aqueous ammonia in such a manner that the sulfur ous acid produced by the reaction is transfolrmed into a practically insoluble metallic sa t.

2. The process for producing aminoanwith aqueous ammonia-in presence of barium thraquinones,-Wl1ic11 consists in heating an chlorid. alkali salt of anthraquinone sulfonic acid In testimom where f, I mix n I slgnature with aqueous ammonia in presence of a soI- v in presence of we witnesses.

5 uble'barium salt. I 1 v RI DOLF UHLENHUTH.

3. The process for producing aminoan- Vitnessesr thraquinones, whichconsists in heating an JEAN 'GRUND, alkali salt of anthraquil'lone. sulfonic acid CARL GRUND. 

